Los Angeles is pursuing possibly the most ambitious rail transit investment program in the U.S. by creating the Expo Line. A new peer-reviewed research report from the Mineta Transportation Institute provides an understanding of the potential impacts of that project by assessing changes in transit use of nearby residents and nearby bus service.

The study, “Changes in Transit Use and Service and Associated Changes in Driving near a New Light Rail Transit Line,” is one of the first that tracks changes in travel behavior before and after the opening of new light rail transit service. 

"Two important and linked lessons came out of this study," said Dr. Hilary Nixon, one of the principal investigators. "First, changes in bus service coincident with the introduction of new light rail transit can negatively affect the overall transit ridership in the corridor. Second, households living near new Expo Line light rail stations reduced their vehicle miles traveled (VMT), but those households living near bus stops that were eliminated increased their VMT."

This second observation is not definitive, Dr. Nixon cautioned, but it suggests the possibility that bus service is a complement to rail transit service, at least for driving reduction.

The policy implications of this research suggest that transit agencies should think more carefully about bus and rail transit service, particularly when new rail transit is introduced. The researchers suggest that transit agencies take a more holistic view of travel impacts, including driving as well as transit. In addition, changes to bus service should be carefully crafted not only to maximize use of new rail transit service, but also to facilitate changes in travel behavior consistent with a shift away from auto-mobility.

The new Expo Line rail service extends south and west from downtown Los Angeles along Exposition Blvd. This report focuses on the first phase of the line's construction, which opened in two stages in April and June 2012. It runs 8.7 miles from downtown Los Angeles westward to Culver City, near the junction of the 405 and 10 Freeways.

This report could be valuable to planners and policy makers because LA Metro's long-range plan has committed funds to six new rail transit lines scheduled to open between now and 2019. This would expand the Metro rail network by nearly 50 miles. Other municipalities contemplating similar expansions could benefit, as well, according to the report.